I have the 70 mm. I would have prefered the 150 mm (which is missing in the list) but that was only available with HSM (ultrasonic drive), which was not supported by my ist*D. I think the 100 mm wasn't available when I bought the 70 mm.
All three lenses are excellent macros, no flaws. Thus one has to make his choice by the criterias listed by photoptimist.
I bougth the lens mainly for shooting insects. The 100 mm does not really help to increase the distance if you get into the 1:1 scale. The 150 mm would have been the logical choice. I even entertained the thought of getting a used 200 mm macro.
In every day use the 70 mm proved to be the more versatile lens on APS-C and most insects are quite patient concerning the distance. Also the shorter focal length allows to shoot 100% of the pictures from hand, very convenient when chasing flying insects. All togethter I am quite happy with the 70 mm.
Last edited by Papa_Joe; 06-26-2019 at 12:27 AM.